Process for polymerization of cationically polymerizable monomers

ABSTRACT

A CATALYST SYSTEM FOR PREPARING HOMOPOLMERS AND COPOLYMERS OF CATIONICALLY POLYMERIZABLE MONOMERS WHEREIN THE CATALYST SYSTEM COMPRISES AN ORGANIC HALIDE COCATALYST AND A CATIONIC CATALYST OF THE TYPE AL(M)2R, WHERE M IS A BRANCHED OR STRAIGHT-CHAIN C1 TO C12 ALKYL AND R IS M, HYDROGEN OR HALOGEN.

United States Patent 3,560,458 PROCESS FOR POLYMERIZATION OF CATION- ICALLY POLYMERIZABLE MONOMERS Joseph P. Kennedy, Cranford, and Francis P. Baldwin,

Summit, N.J., assignors to Esso Research and Engineering Company, a corporation of Delaware No Drawing. Continuation-impart of application Ser. No. 364,295, May 1, 1964. This application Mar. 13, 1968, Ser. No. 712,605

Int. Cl. C08d 3/02 U.S. Cl. 26085.3 15 Claims ABSTRACT OF THE DISCLOSURE A catalyst system for preparing homopolymers and copolymers of cationically polymerizable monomers wherein the catalyst system comprises an organic halide cocatalyst and a cationic catalyst of the type Al(M) R, where M is a branched or straight-chain C to C alkyl and R is M, hydrogen or halogen.

BACKGROUND OF THE INVENTION This application is a continuation-in-part of application S.N. 364,295, filed May 1, 1964.

It is known that certain halogen containing ethers in combination with organoaluminum compounds initiate the polymerization of trioxa-cycloalkanes by a ring opening mechanism, see for example, U.S. Pat. 3,197,420.

Certain prior art disclosures indicate that isobutylene may be polymerized to high molecular weights in the presence of solvents having a dipole moment greater than 1, see for example, U.S. Pat. 3,123,592.

SUMARY OF INVENTION Surprisingly, it has been found that cationically polymerizable monomers may be homopolymerized or copolymerized to high molecular weigths in the presence of a Friedel-Crafts type catalyst in the presence of an organic halide promoter containing at least one dissociable halogen. The activity of the catalyst is independent of the polarity of the solvent and is adversely afiected by certain oxygen containing organic halides.

DETAILED DESCRIPTION OF THE INVENTION The invention relates to the use of a novel catalyst system for the polymerization of cationically polymerizable monomers. It further relates to the production of high molecular weight homopolymers and copolymers by cationic initiation of polymerization of monoolefins and multiolefins by means of the novel catalyst disclosed herein.

In particular this invention relates to the polymerization of monoand diolefins with a catalyst system which comprises: (1) a catalyst of the type Al(M) R, where M is a branched or straight chain C to C alkyl and R is selected from the group consisting of M, hydrogen and halogen, and (2) a promoter comprising an organic compound containing a dissociable halogen. More particularly, the promoter component of the present novel catalyst system is represented by the following structural formula:

wherein X is halogen, R is selected from the group consisting of hydrogen, C, to C alkyl, phenyl and C to C alkenyl, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl, C to C alkenyl and phenylalkyl and R is selected from the group consisting of Patented Feb. 2, 1971 Substitution of the above structural formula radical for R in formula (A) results in the following formula:

wherein X, R R and R are as defined above. The compounds represented by structural formula (-B) contain two dissociable halides and may be considered as merely multiples of those compounds represented by structural formula (A). In addition, to the promoters represented by structural formula (A) and (B), the promoter component of the present novel catalyst system can further be selected from the dihalomethanes, e.g., dichloromethane and dibromomethane.

Still more particularly, this invention relates to the high molecular weight polymers and copolymers of isoolefins produced with the above-described novel catalyst system. Most particularly, this invention relates to the production of high molecular weight butyl type rubbers, i.e., a copolymer of an isoolefin, such as isobutene, and multiolefin, such as isoprene, at temperatures considerably higher than have heretofore been possible.

Butyl type rubber polymers produced by a Friedel- Crafts catalyst system have long been known in the art. See, for example, chapter 24 of Synthetic Rubber by G. S. Whitby, John Wiley and Sons, Inc. (1954) and U.S. Pat. 2,356,128 to Thomas et al., among many others. The catalyst most frequently used for the production of butyl type rubber has been aluminum chloride dissolved in methyl or ethyl chloride solution. However, aluminum chloride is only sparingly soluble in alkyl halide solutions and this low solubility has given rise to many difllculties in the control of the butyl rubber polymerization reaction.

It has been proposed to polymerize and copolymerize hydrocarbons of the olefin series by means of a catalyst represented by the formula R AlX where R is a monovalent alkyl hydrocarbon radical, X is halogen and m: and n are integers from 1 to 2 inclusive and m+n=3. See, for example, U.S. Pats. 2,220,930 and 2,387,517. Coassigned U.S. patent application, Ser. No. 266,267, filed Mar. 20, 1963, now U.S. Pat. 3,350,686, describes a liquid catalyst system for the production of butyl type rubbers. The catalyst system described therein comprises an alkyl aluminum halide with a ratio of alkyl groups to halogen atoms corresponding approximately to the formula AIRX where R is an alkyl group and X represents a halogen atom. It was pointed out in that application that where the ratio of alkyl groups to halogen atoms is reversed, i.e., the formula is AlR X, no polymerization will occur.

It has been further reported by some workers that tertiary butyl halides can have a poisoning eifect on Friedel- Crafts polymerization catalysts, e.g. AlCl It has also been proposed that the incorporation of between 6 and parts of tertiary butyl halide per million parts of hydrocarbon feed promotes the polymerization and activates the Friedel-Crafts catalyst. See, for example, U.S. Pat. 2,581,154. It has, however, been impossible up to this time to prepare elastomeric products from isoolefins, such as isobutene, with a dialkyl-aluminum halide, trialkylaluminum or dialkylaluminum hydride catalyst.

The present invention provides a soluble catalyst system for the production of butyl type rubber and other polymers derived from cationically polymerizable monomers which will alleviate many operating difficulties and provide other benefits such as a more uniform product, a small amount of catalyst residue in the product and an ease of handling a liquid catalyst. Use of the novel catalyst system of the present invention provides improved catalyst efliciency together with greater accuracy and control of the polymerization process. The novel catalyst system of the present invention further provides a catalyst system which permits the production of high molec ular weight homopolymers and copolymers of monoolefins at considerably higher temperatures, e.g., about 30 C., than have heretofore been possible. The present invention permits the polymerization of monoolefins and polyolefins in either a conventional alkyl halide solvent, an aliphatic hydrocarbon solvent or carbon disulficle solvent or permits their polymerization in little or no solvent to yield an elastomeric product. In the latter case, the unreacted monomer mixture functions as the diluent.

The exact nature and objects of this invention will be more clearly perceived and fully understood by referring to the following description.

It has now been discovered that elastomeric or thermoplastic polymers may be produced by polymerizing monoolefins or multiolefins with a catalyst system comprising (1) a catalyst of the type A1(M) R where M is a branched or straight chain C to C alkyl and R is selected from the group consisting of M, hydrogen and halogen and (2) a promoter selected from the group consisting of dihalo methanes and organic halogenides represented by the following structural formula:

A wherein X is halogen, R is selected from the group consisting of hydrogen, C, to C alkyl, phenyl, and C to C alkenyl, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl, C to C alkenyl and phenylalkyl and R is selected from the group consisting of C to C alkyl, C to C alkenyl, phenyl, phenylalkyl, alkyphenyl, C to C cycoalkyl and wherein R R and X are as defined above and R is selected from the group consisting of phenylene, biphenyl, a,w-diphenylalkane and (CH wherein n is an integer of from 1 to 10.

The olefin polymerization feeds employed in connec tion with the above-described catalyst system are those olefinic compounds, the polymerization of which are known to be cationically initiated. Preferably, the olefin polymerization feeds employed in connection with the above-described catalyst system are those olefinic compounds conventionally used in the preparation of butyl type rubbery polymers. The polymers are prepared by reacting a major portion, e.g., about 70-99.5 parts by weight, preferably 85-99.5 parts by weight, of an isoolefin, such as isobutene, with a minor portion, e.g., about 30-05 parts by weight, preferably -05 parts by weight, of a multiolefin, such as butadiene or isoprene. The isoolefin, in general, is a C to C compound, e.g., isobutene or Z-m'ethyl-l-butene, 3-methyl-l-butene, 2-methyl-2-butene, and 4-methyl-1-pentene. The multiolefin, in general, is a C to C conjugated diolefin, e.g., isoprene, butadiene, 2,3-dimethyl-1,3-butadiene, myrcene, 6,6-dimethylfulvene and piperylene. The preferred polymer is obtained by reacting 95-99.5% by weight of isobutene with 0.5 5% by Weight of isoprene.

Cyclodiolefin compounds, such as cyclopentadiene and methylcyclopentadiene, as well as compounds such as 5- pinene and divinyl benzene may be copolymerized with the isoolefin either in addition to the diolefin or in place of the diolefin. These additional diolefins may be incorporated in amounts up to about 6% by weight, based on isoolefin, preferably in amounts from 0.3 to about 2.0 wt. percent. Copolymers formed from combinations of the above compounds have improved ozone resistance and compare favorably in molecular weight with the butyl rubber copolymers produced by the practice of this invention.

In addition to the above-described butyl type olefin feeds, isoolefins, such as isobutene, may be homopolymerized or copolymerized with other polymerizable monoolefins, such as styrene, with the instant novel catalyst system. Furthermore, multiolefins such as butadiene and isoprene may be homopolymerized or copolymerized with other monoolefins of this invention.

The solvents which can be used in the practice of this invention are the conventional alkyl halide solvents, such as methyl chloride, chlorobenzene, methyl bromide, and carbon tetrachloride. In addition, carbon disulfide, its analogues and homologues may be used. The preferred solvent is methyl chloride. Moreover, aliphatic hydrocarbon solvents, mixtures thereof, or mixtures with halogencontaining solvents, that are liquid at the polymerization temperature may be used in the practice of this invention. These include C through C saturated aliphatic and alicyclic hydrocarbons, such as pentane, isopentane, hexane, isooctane, methylcyclohexane, cyclopentane, cyclohexane, etc. Because of the solubility of the catalyst system used in the present process, only very small amounts of solvent, e.g., less than 10 wt. percent, need be used.

The catalyst system, which is an essential feature of the present novel process, comprises (1) a catalyst of the type Al(M) R, where M is a branched or straight chain C to C alkyl and R is selected from the group consisting of M, hydrogen and halogen, and (2) a promoter comprising an organic compound containing a dissociable halogen. For purposes of brevity, the compounds represented by the formula Al(M) R will be referred to as the catalyst though it should be realized that these compounds will, by themselves, not ordinarily act as a catalyst in the olefin polymerizations of this invention. The organic compound containing the dissociable halide will be referred to as the promoter.

The catalyst components utilized in the present novel catalyst system are those compounds represented by the general formula Al(M) R, where M is a branched or straight chain alkyl group having from 1 to 12 carbon atoms and R is selected from the group consisting of M, hydrogen and halogen. Suitable catalyst compounds coming within the scope of the above general formula include: diethyl aluminum chloride, dipropyl aluminum chloride, diisopropyl aluminum chloride, dibutyl aluminum chloride, diisobutyl aluminum chloride, dipentyl aluminum chloride, dihexyl aluminum chloride, didecyl aluminum chloride, diethyl aluminum bromide, diisobutyl aluminum bromide, dioctyl aluminum bromide, didodecyl aluminum bromide, diethyl aluminum iodide, dibutyl aluminum iodide, diheptyl aluminum iodide, dinonyl aluminum iodide, ethyl propyl aluminum chloride, propyl butyl aluminum chloride, ethyl propyl aluminum bromide, diethyl aluminum hydride, dibutyl aluminum hydride, dihexyl aluminum hydride, trimethyl aluminum, triethyl aluminum, methyl diethyl aluminum, dimethyl ethyl aluminum, triisobutyl aluminum, trihexyl aluminum, etc. The preferred catalyst is diethyl aluminum chloride which will be used here for illustrative purposes.

Diethyl aluminum chloride, which is commercially available, is a clear colorless liquid with a melting point of 74 C., and a boiling point of 208 C. The substance is highly reactive with oxygen and will burst into flames in air and react violently with water. It is miscible with saturated aliphatic and alicyclic hydrocarbons, chlorinated hydrocarbons, carbon disulfides, etc. Diethyl aluminum chloride may be prepared from aluminum triethyl and aluminum chloride according to the following formula:

The promoters which form the second component of the instant two-component catalyst system for the present novel process contain a dissociable halogen and are selected from the group consisting of dihalomethanes and organic halogenides represented by the following formula:

wherein X is halogen, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl and C to C3 alkenyl, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl, C to C alkenyl and phenylalkyl and R is selected from the group consisting of C to C alkyl, C to C alkenyl, phenyl, phenylalkyl, alkylphenyl, C to C cycloalkyl and wherein R R and X are as defined above and R is selected from the group consisting of phenylene, biphenyl, a,w-diphenylalkane and (CH wherein n is an integer of from 1 to 10.

The phenylalkyl and alkylphenyl radicals described above are univalent radicals which are respectively derived by the removal of a hydrogen atom from the alkyl side chain of an aromatic hydrocarbon and by the removal of a hydrogen atom from the ring of an alkyl substituted aromatic hydrocarbon. In general, the alkyl groups can be branched or straight chain and can vary in length from 1 to about 12 carbon atoms and advantageously will vary in length from 1 to about 6 carbon atoms. The aromatic hydrocarbon of the alkylphenyl radical can be monosubstituted or polysubstituted.

The promoters of the present novel catalyst system are characterized by the fact they ionize, i.e., they dissociate, under the conditions prevailing, into a halogen anion and a carbonium ion. The promoters are further characterized by a structural similarity. For the most part, the halogen of either the monohalogenated or dihalogenated compounds represented by Formulae A and B is attached to a carbon atom selected from the group consisting of a tertiary carbon atom, a secondary carbon atom, an allylic carbon atom and a benzylic carbon atom. In addition to the foregoing, it has somewhat surprisingly been found that aliphatic and aromatic halogenides containing the isobutyl halide grouping are also effective as promoters in the present catalyst system.

Examples of suitable promoter compounds representative of structural Formula A include: isopropyl chloride, isopropyl bromide, isobutyl chloride, secondary butyl chloride, secondary butyl iodide, tertiary butyl chloride, tertiary butyl bromide, 2-chlorohexane, tri-n-butyl chloromethane, 9-chloro-heptadecane, 2-chloro-2-methyldecane, dimethyl phenyl chloromethane, methyl ethyl phenyl chloromethane, methyl pentyl phenyl bromomethane, diphenyl chloromethane, triphenyl chloromethane, methyl phenyl chloromethane, benzyl chloride, benzyl bromide, benzyl fluoride.

Still other suitable examples of promoter compounds representative of Formula A include: 1-chloro-butene-2, allyl chloride, methallyl chloride, crotyl chloride, 3-chlorobutene-l, 2-ethyl-3-chloropropene-1, 2-hexyl-3- chloropropene-l, 1-chloro-hexene-2, l-bromo-heptene-Z,

dimethyl benzyl bromomethane, 3-phenylpropyl dimethyl chloromethane, methyl dibenzyl chloromethane, n-butyl benzyl chloromethane, o-methyl benzyl chloride, o-propyl benzyl chloride, p-hexyl benzyl chloride, p-octyl benzyl bromide, cyclopropyl dimethyl chloromethane, cyclopentyl methyl chloromethane, cyclodecyl methyl chloromethane and cyclohexyl bromomethane.

Further examples of promoter compounds and those which are specifically representative of the above recited structural Formula B include:

2,5-dichloro-2,5-dimethyl hexane, p-dichloromethylbenzene, 2,4-dichloropentane, 2,4-dichloro-2,4-dimethy1 pentane, 5,7-dibromo-5,7-dimethyl undecane, 5,8-difiuoro-5,8-dimethyl dodecane, 3,5-dichloro-5-methyl hexene-l, 2,5-dichloro-2,5diphenyl hexane, 1,4-dichloro-1,1,4,4-tetraphenyl butane, 2,5-dichloro-2,5-di(p-methylphenyl)-hexane, 2,5-dichloro-2,S-dibenzyl hexane, 2,7-dibromo-2,7-dicyclopropyl octane, 4,4-dichloromethylbiphenyl and 4,4'-dichloromethyl-diphenylethane.

The amount of promoter to initia e polymerization varies with the type and activity of the promoter employed. In the case of tertiary butyl chloride and benzyl chloride as little as 0.001 mole of promoter per mole of diethyl aluminum chloride can initiate polymerization whereas in the case of secondary butyl chloride, about 2 moles of promoter per mole of diethyl aluminum chloride is necessary to initiate polymerization. In general, the ratio of promoter to catalyst will vary between about 0.0001 mole and about 30 moles of promoter per mole of catalyst, and will advantageously range between about 0.001 mole and about 20 moles. For the most active promoters, the ratio of promoter to catalyst will most advantageously vary between about 0.01 mole and about 5 moles of promoter per mole of catalyst and preferably between about 0.5 mole and 1.5 moles.

As heretofore mentioned, the present catalyst system permits butyl type rubber polymerizations to be carried out at considerably higher temperatures than have previously been possible. In general, temperatures ranging from about 0 C. to about C. may be employed. Preferably the polymerizations will be carried out at a range of from about 27 C. to about 78 C. The pressure employed forbutyl type rubber polymerizations utilizing the instant novel process will generally be at or near atmospheric.

The various aspects and modifications of the present invention will be made more clearly apparent by reference to the following description and accompanying examples.

Molecular weights of the polymers prepared in the subsequent examples were obtained from viscosity measure ments of 0.1% polymer solutions in diisobutylene at 20 C. The intrinsic viscosities were obtained from single measurements using the slope of the curve, In /C (inherent viscosity/concentration). The viscosity average molecular weights were calculated from the equation:

ln M =12.48+1.565 1n Physical properties of vulcanizates were determined according to the methods described in ASTM D 4l2-5 1T.

Example 1 In runs 15, comparative experiments were carried out with only the promoter being changed in each run. Thus, 0.00575 mole of diethyl aluminum chloride was mixed with 0.627 mole (50 ml.) of isobutene in 50 ml. of methyl chloride and stirred at *50 C. Even with vigorous agitation over a period of about 10 minutes, no polymerization occurred. To separate quiescent mixtures of this "composition, the various promoters were added. In run 1, the promoter solution was prepared by diluting of between 50 and about 60 and a molecular weight of between 350,000 and about 400,000.

TABLE II Amount of promoter Mole Temp, introduced, Conversion, Mo]. wt. Iodine percent; C. Promoter ml. percent X10- number unsaturation 0. 03 71 117 0. 06 31. 2 288 0. 45 14. 7 280 32. 9 352 26. 7 336 0. 21 11. 4 580 u d sec utyl C 2. 00 75. 8 113 13, 27 Undiluted isopropyl 01. 0.5 73 133 Butyl 218 100 AlCls, catalyst 350-400 AlEtzCl catalyst treated with NaCl. 0 0.02 mole AlEt Cl in the B-3 feed.

11 Fresh AlEtzCl prepared by slowly filtering through Irittcd glass under nitrogen atmosphere (moisture content p.p.n1.).

0.5 ml. of tertiary butyl chloride with 50 ml. of methyl chloride. Similarly, in run 2, the promoter solution was prepared by diluting 10 ml. of isobutyl chloride with 10 ml. of methyl chloride. Promoters for runs 3, 4 and 5 were utilized in an undiluted form. Experimental details and results of runs l-5 are summarized in Table I.

The data in Table II show that diethyl aluminum chloride may be used as a catalyst for the polymerization of butyl type rubbers, provided that a suitable promoter is present and that such nibbers compare favorably with commercially available Enjay Butyl 218 with regard to molecular weight and mole percent unsaturation.

TABLE I Grams Mole of product promoter Product M01. wt. per mole Introduced yield (viscosity) of pro- Promoter X (g s) X10 moter Run:

1 t-Butyl chloride 0. 0 7 1 607 143, 000 Isobutyl chloride... 0. 058 2. 4 331 Q Sec butyl chloride.. 1. 2 4. 5 705 369 Isopropyl chloride 1. 14 30. 3 253 2, 680 5 Methyl chloride Large None The data in Table I show that diethyl aluminum chloride may be used as a catalyst for the polymerization of isobutene, provided that a suitable promoter is employed. The data also show that methyl chloride, a non-dissociable halide, is inoperative as a promoter in the present novel process.

Example 2 In runs 6-13, a monomer mixture consisting of 100 ml. of 97 volume percent isobutene and 3 volume percent isoprene (B*3 feed) was employed. A typical polymerization was carried out as follows:

A charge consisting of 100 ml. of B-3 feed and 90 ml. of methyl chloride was placed in a reaction vessel and stirred at a selected polymerization temperature. After thermoequilibrium had been attained, 1.3 ml. (0.01 mole) of diethyl aluminum chloride dissolved in 10 ml. of methyl chloride was added. Thereafter, precooled promoter was introduced dropwise into the quiescent mixture. Polymerization started immediately upon promoter introduction and was terminated with chilled methanol.

The promoter solution of runs 611 was prepared by dissolving 1 ml. of tertiary butyl chloride in 100 ml. of methyl chloride. This corresponded to a concentration of 0.0915 mole/liter. Experimental details and results are Portions of the polymerization products of runs 9-13 were cured for 10, 20, 30, 40 and minutes at a temperature of 307 F., according to the following cure recipe.

Parts per hundred parts of rubber Isobutene-rsoprene rubber HAF black (high abrasion furnace black) 50 Necton 60 1O ZnO 5 Sulfur 2 Stearic acid 1 PBN (phenyl-p-naphthylamine) 1 Methyl tuads (tetramethyl thiuram disulfide) 1 Altax (benzothiazyl disulfide) 1 TABLE III Minutes cured 307 F.

'r M E T M E T M E T M E T M E 480 2, 240 980 2,280 400 2,030 880 2,120 240 89 2,350 590 090 880 350 1,150 500 1,250 1,120 350 1,350 500 1,520 620 1,780 78 370 860 2,660 730 090 2,000 1,170 570 2,730 1,270 550 NorE.T=Tensile, p.s.i.; M=300% modulus, p.s.i.; E=Elongation, percent. summarized and compared to Enjay Butyl 218 in Table EX 1 3 II. Enjay Butyl 218 is a commercial grade of butyl ampe rubber prepared from isobutene and isoprene. It has a mole percent unsaturation of between about 1.5 and In runs 14 and 15, 0.00575 mole of diethyl aluminum chloride was mixed with 0.627 mole (50 ml.) of isobutene about 2.0, a Mooney Viscosity (ML 3 min. at 260 F.) 7 in 50 ml. of methyl chloride and stirred at 50 C. No

polymerization occurred. Thereafter precooled promoter was introduced dropwise into the quiescent mixture. Polymerization started immediately upon promoter introduction and was terminated with chilled methanol.

In runs 16 and 17, a charge consisting of 10 ml. of isobutene and 10 ml. of methyl chloride was placed in a reaction vessel and stirred at 50 C. To this monomer-sol- 10 at -50 C. No polymerization occurred. A promoter solution was prepared by adding 0.1 ml. of 1-chloroethylbenzene to 10 ml. of methyl chloride. Four drops of this solution were gradually added to the monomer-solventcatalyst mixture. In all four runs, polymerization was terminated with cold methanol and the product dried in vacuo at 60 C. Table V summarizes the results obtained.

TABLE V Grams Moles of product promoter Product Mol. wt. per mole of Time for Promoter introduced yield, g. 10- promoter run, min.

Run

18.. Diphenylehloromethane 6.9)(10- 0. 934 204 13, 500 25 19. Benzylchlorlde 3. 7X10- 0. 195 784 527, 000 26 20 Trlphenylchloromethan 1. 8X10- 0. 833 314. 5 4, 600 200 21 l-chloroethylbenzeue 9. 2 10- 0.295 325 31,900 3 vent mixture was added 1 ml. of a diethyl aluminum chloride solution prepared by dissolving 1.3 ml. of diethyl aluminum chloride in 8.7 ml. of methyl chloride. No polymerization occurred. A promoter solution was prepared by dissolving 0.25 vml. of crotyl chloride (run 16) and 0.25 ml. of 3-chloro-l-butene (run 17) in 25 ml. of methyl chloride. After the reaction vessel reached thermoequilibrium, the precooled promoter solution was added dropwise to the quiescent mixture. Polymerization started immediately and after about minutes was terminated with chilled methanol. The results of runs 14-17 are summarized in Table IV.

Example 5 (Runs 22-28) 20 Various runs were made utilizing a catalyst system of diethyl aluminum chloride and 2,5-dichloro-2,5-dimethyl hexane. The procedure used was identical to that of the previous examples in that the monomer and solvent were initially mixed, followed by the addition of the catalyst. Thereafter, the promoter was added dropwise to the quiescent mixture. In runs 22-27, the monomer charge consisted of isobutene whereas in run 28 the monomer The data in Table IV show that diethyl aluminum chloride may be used as a catalyst for the polymerizacharge consisted of 97 ml. of isobutene and 3 ml. of isoprene. Results of these runs are tabulated in Table VI.

TABLE VI Amount of Solvent AlEtgCl Temperapromoter Monomer CH3C1, catalyst, ture introduced Product, Percent Mol. wt: teed, ml. ml. mole 0. moles grams conversion x10- 25 25 2. 5x10- -27 4. 55x10- 0. 77 4. 3s 30. 2 25 25 2. 5x10 4. 515x10 4. 1s 23. a 507 25 25 2. 5 10- -73 4. 10- 9. 67 54. 6 1, 387 100 100 1.05x10- -100 9 07x10- 10.0 14.1 640 100 100 1.05 10 -27 3 73x10 300 42.3 346 200 1.03 10- -9 75.6 10 45.0 31.7 105 100 100 1. 05x10- -28 5 67 10 13.0 18.3 215 tion of isobutene provided that a halogenated organic Portions of the product of run 28 were compounded compound in which the halogen is in the allylic position accordmg to the cure recipe of Example 2 and cured for is used as a promoter. 10, 20, 40 and minutes respectively at 307 F. Results Example 4 (Runs 1841) 5: 0T; g1: ilrliipections of the physical propertles are listed in For runs 18, 19 and 20, a stock solution was prepared TABLE V1I 2 by mixing 100 ml. of isobutene (1.254 moles) and 100 ml. of methyl chloride at 50 C. Thereafter, 0.01 mole 10 minutes cured at 307 F.: of diethyl aluminum chloride was added and the mixture T stirred. No polymerization occurred. Five ml. of this 60 M No cure stock solution were withdrawn for each run and to each E sample were added promoter solutions prepared as fol- 20 minutes cured at 307 F.: lows. In run 18, 5 drops of a solution prepared by dis T 2,410 solving 0.5 gram of a diphenylchloromethane in 50 ml. M 480 of methyl chloride were added. For run 19, 0.5 ml. of E 740 benzylchloride was mixed with 50 ml. of methyl chloride; 40 minutes cured at 307 F.: 1 ml. of this solution was further diluted with 40 ml. of T 2,570 methyl chloride and 5 drops of this solution were used M 800 to promote the polymerization. In run 20, 0.5 gram of E 620 triphenylchloromethane were added to 5 ml. of methyl 60 minutes cured at 307 F.: chloride and 0.5 ml. of this solution was used to promote T 2,670 the reaction. Polymerization commenced immediately in M 920 runs 18 and 19 and began slowly in run 20. In run 21, E 600 10 of lsobutene 10 of methyl chlonde and Norn.--T:tensile, p.s.i. M:300% modulus, p.s.i. E:elo11- ml. of diethyl aluminum chloride were mixed and stirred gaition, percent,

Example 6 Five ml. of isobutene and 0.2 ml. of AlEt Cl were mixed and stirred at C. No reaction occurred. Subsequently, ml. of isobutene and 5 m1. of spectroquality dichloromethane were mixed and stirred at 0 C. No reaction occurred in this instance. To this second solution was added 1 drop (0.025 ml.) of purified AlEt Cl. Sudden, vigorous polymerization took place yielding a product of viscosity average molecular weight of about 7000.

Dibromomethane (8.3 mole) was slowly added to a quiescent charge of 5 ml. of isobutene, 5 ml. of methyl chloride and 0.065 ml. (5x10 mole) of AIEt CI at -50 C. Polymerization commenced immediately upon the introduction of the dibromomethane and was terminated after 40 minutes with cold methanol. The resulting polymer had a viscosity average molecular weight of about 640,000. A similar run utilizing an isobutene-isoprene feed yielded a polymer with a viscosity average molecular weight of about 136,300.

Example 6 illustrates that dihalomethanes can be utilized as promoters in the present novel catalyst system.

Example 7 A monomer mixture consisting of 97 m1. of isobutene and 3 ml. of isoprene along with 100 ml. of methyl chloride was charged to a reaction vessel and stirred at 100 C. To this monomer-solvent mixture were added 1.8 ml. (0.1 mole) of diethyl aluminum hydride dissolved in 10 ml. of methyl chloride. No polymerization reaction occurred. Subsequently, a solution of 0.5 ml. of tertiary butyl chloride in 50 ml. of methyl chloride was prepared and added dropwise to the quiescent monomer-solventcatalyst mixture. Polymerization started immediately. A total of 13.9 ml. (0.012 mole) of the tertiary butyl chloride promoter solution was added during the polymerization. The reaction was terminated at a low conversion by introducing cold methanol. A white rubbery solid was obtained having a viscosity average molecular weight of 738,000 (I.V.=1.934), an iodine number of 27.8 and a mole percent unsaturation of 4.1.

Example 8 Runs 29 and 30 were made using a catalyst system comprising diisobutyl aluminum hydride and tertiary butyl chloride. In run 29, 100 ml. of isobutene and 100 ml. of methyl chloride were mixed and stirred at temperatures of 30 C., -50 C., -78 C. and 100 C. After thermoequilibrium was attained, 0.01 mole (1.8 ml. of catalyst in 10 ml. of CH Cl) of diisobutyl aluminum hydride was added to the monomer-solvent mixture and stirring was continued for about 10 minutes. No polymerization reaction occurred. A promoter solution was prepared by mixing 0.5 ml. of tertiary butyl chloride and 10 ml. of methyl chloride and portions of this solution were added dropwise to the monomer-solventcatalyst mixture. Polymerization began upon promoter introduction and was terminated with cold methanol. The polymer product was washed and dried in vacuo at 60 C. Run 30 was a repeat of run 29, except that the monomer charge consisted of 97 ml. of isobutene and 3 ml. of isoprene instead of 100 ml. of isobutene. Table VIII summarizes the results of the two runs.

TABLE VIII Run 29 Temperature, C 30 --50 78 l00 Mol. wt. 10- 202 239 573 27 Product, grams 4.0 30. 7 3. 6 57. 2 Percent conversion 5. 43. 2 5.08 80. 7 Grams product per mole of promoter. 4, 820 46, 500 6, 670 1, 245 Moles of promoter introduced X10 0.83 0. 66 0. 54 4. 6

Run 30 Temperature, C -30 50 -78 l00 M01. wt. 10- 63 210 314 897 Product, grams. 29. 5 13.1 1. 3 1.0 Percent conversion 41. 6 18. 5 1. 8 1. 41 Iodine number 8. 7 18. 5 16.9 19. 1 Mole percent unsatnration 1. 28 2. 72 2. 48 2. 81 Grams product per mole of promoter.-." 11, 800 4, 260 1, 810 855 Moles of promoter introduced X10 2. 5 3. 1 0. 72 1. 17

Example 9 In run 31, ml. of isobutene and 100 ml. of methyl chloride were mixed and stirred at 50 C. Thereafter, 0.01 mole of diisobutyl aluminum chloride in 10 ml. of methyl chloride was added. Following a period of inactivity, 19 drops (4.4 10 mole of te-butyl chloride) of a promoter solution, prepared by mixing 0.5 ml. of tertiary butyl chloride and 50 ml. of methyl chloride, were added to initiate polymerization. A total of 6.1 grams of product having a viscosity average molecular weight of 192,000 were recovered. Run 32 was a repeat of run 31 except that (1) the monomer charge consisted of '97 ml. of isobutene and 3 ml. of isoprene instead of 100 ml. of isobutene and (2) a total of 7.6 l0 mole of tertiary butyl chloride was added to initiate polymerization. This run yielded 32 grams of product which had a viscosity average molecular weight of 299,000, an iodine number of 9.8 and a mole percent unsaturation of 1.44.

Example 10 A charge consisting of 100 ml. of isobutene, 100 ml. of methyl chloride and 0.020 mole of AlEt Cl was mixed and stirred for minutes at 50 C. No reaction occurred. A promoter solution prepared by mixing 0.5 ml. of tertiary butyl bromide in 50 ml. of methyl chloride, was added dropwise over a period of 33 minutes to the monomer-solvent-catalyst mixture. A total of 53x10- mole of tertiary butyl bromide was added. The polymerization reaction was terminated with cold methanol and the resultant product recovered and dried in vacuo at 60 C. A total of 6.0 grams of product, having a viscosity average molecular weight of 458,000, were recovered. This represents a theoretical promoter efficiency of 11,300 grams of product per mole of promoter.

Example 11 Runs 33 and 34 were performed using a catalyst system comprising diethyl aluminum bromide and tertiary butyl bromide. In run 33, 100 ml. of isobutene and 100 ml. of methyl bromide were mixed and stirred at temperatures of 30 C., -50 C., 78 C., and 100 C. After thermoequilibrium, 0.01 mole of diethyl aluminum bromide (1.29 ml. of catalyst in 10 ml. of CH Br) 'Was added to the monomer-solvent mixture and stirring was continued for about 10 minutes. No polymerization occurred. A promoter solution was prepared by mixing 0.5 ml. of tertiary butyl bromide and 50 ml. of methyl bromide and portions of this solution were added dropwise to the reaction mixture. Polymerization started soon thereafter and was terminated with cold methanol. The polymer product was washed and dried in vacuo at 60 C. Run 34 was a repeat of run 33 except that a monomer charge of 97 ml. of isobutene and 3 ml. of isoprene Was 13 substituted for the 100 m1. of isobutene. Table IX summarizes the results of these two runs.

B-6 contained 94 volume percent isobutene and 6 volume percent isoprene.

TABLE IX Run 33 Temperature, C 30 -50 78 100 M01. wt. l- 170 320 908 202 Product, grams. 5. 3 10. 0 12. 0 6. 9 Percent conversi0n 7. 6 14. 3 17. 2 9. 9 Grams product per mole of promoter- 57, 00 103, 000 172, 000 23, 300 Moles promoter introduced- 9 2 1O- 9.7)(- 6.6)(10- 2 97x10- Run 34 Temperature, C 30 50 -78 100 M01. wt. X10- 133 184 565 73 12 number 10. 9 9. 5 7. 2 9.2 Mole percent unsaturatio 1. 6 1. 4 1. 06 1. 35 Product, grams 23. 9 20. 5 15. 9 12. 5 Percent conversion. 34. 1 28. 3 22. 7 17. 9 Grams product per mole of promote 70, 200 89, 200 88, 500 14, 900 Moles promoter introduced- 3. 4 10 2. 3X10- 1. 8X10- 8. 4X10- Example 12 In runs 35-37, catalyst systems comprising an aluminum trialkyl and tertiary butyl chloride were investigated. The aluminum trialkyls used in these runs were trimethyl aluminum, triethyl aluminum and triisobutyl aluminum, respectively. A charge of 100 ml. of isobutene and 100 ml. of methyl chloride were mixed and stirred at selected temperatures. After thermoequilibrium, the aluminum trialkyl catalyst was added and stirring 'was continued for 5 minutes. No reaction occurred. A tertiary butyl chloride promoter was thereupon added to initiate polym erization. Results of these runs are tabulated in Table X.

B-8 contained 92 volume percent isobutene and 8 volume percent isoprene.

TABLE X Run 35 20 C. 30 C. 50" C 78 C. 96" C.

Mole catalyst A1(CH3)3 0.01 0.01 0. 01 0. 01 0. 01 Mole promoter X10 0.27 O. 133 1.14 1. 16. 9 Percent conversion. 27. 2 3. 6 41. 5 5. 3 0. 7 Molecular weight 10- 113 136 158 310 133 Run 36 C. 30 C. 50 C 78 C. 96" C Mole catalyst A1(C2H 0. 00025 0.00025 0. 01 0. 0095 Mole promoter X10 0. 275 0.027 0. 12 0. 084 Percent conversion. -75 -10 1. 0 9. 5 Molecular weight X10 74 113 206 Run 37 20 0. C. C 78 C 96 C Mole catalyst Al(IC4Hn)a 0. 01 0. 01 0.01 0. 01 Mole promoter 10 1.0 1. 46 0.57 11.6 Percent conversion- 20. 3 43. 5 13. 0 1. 5 Molecular weight X10 40.4 46 94 157 Example 13 A study of the efiect of temperature on the polymerization of is0buteneis0prene mixtures was made. Mixtures of isobutene and isoprene were prepared and designated B-O, B-3, B6 and 13-8. The compositions of these mixtures were as follows: B-O contained 100 volume percent isobutene. B3 contained 97 volume percent isobutene and 3 volume percent isoprene.

tration was 0.0915 mole per liter in methyl chloride. After 10-15 minutes of stirring, the tertiary butyl chloride promoter solution was introduced dropwise into the quiescent monomer-solvent-catalyst mixture. Polymerization started immediately. Conversions were controlled by the amount of promoter added and were kept low to maintain initial monomer concentration, but high enough to obtain a suflicient sample for compounding. The results are set forth in Table XI.

TABLE XI Temperature, C.

B-Nulnber 40 60 78 100 Promoter solution added, ml 0.3 0. 18 0. 21 0.25 Polymer, g 1. 4. 3 7 12 Percent conversion 4. 3 12. 3 20 34. 2 Intrinsic viscosity 1. 33 1. 835 2. 110 2. 531 Molecular weight X 411 679 853 1, 125 I2 NO B-3:

Promoter solution added, n1 0. 0. 12 0. 12 0. 3 Polymer, 8. 8 10 10. 4 7 Percent conversion 11. 5 14 15 10 Intrinsic viscosity. 0. 920 1. 369 2. 150 2. 000 Percent gel 14. 4 1. 6 Molecular weight XlO-L 234 431 871 797 o 9. 9 9. 7 13. 2 9. 9 B 6Mole percent unsaturation 1. 46 1. 43 1.04 1. 46 Promoter solution added, ml- 0.3 0.24 0. 36 0.6 Polymer, g 4 10. 1 14. 1 7 Percent conversion 5. 6 14. 3 19. 9 10 Intrinsic viscosity 0. 733 1. 193 1. 530 1. 150 Percent gel 1 22 15.9 Molecular weight X101 161 346 512 327 I2 No 19. 4 27. 5 24. 4 22. 4 B Mole percent unsaturation... 2. 96 4.05 3. 59 3. 30

Promoter solution added, ml 0.3 0.45 0. 39 0. 6 Polymer, g 8 14 6. 5 Percent conversion 11. 3 28 20 9. 3 Intrinsic viscosity 0. 096 1. 146 l. 213 1. 270 Percent gel 1 1 36. 5 42 Molecular Weight X10' 140 324 356 382 12 No 27. 4 34. 9 28. 3 26. 6 Mole percent unsaturation. 4. 03 5. 15 4. 17 3. 93

Portions of some of the polymer products of Example 13 were cured according to the recipe set forth in Example 2. Inspections of the resulting vulcanizates are compared to Enjay Butyl 218 and 325 in Table XII. Specifications for Enjay Butyl 218 have been presented in Connection with Example 2. Enjay Butyl 325 is a commercial grade of butyl rubber manufactured by the Enjay Chemical Company. It has a molecular weight of between about 300,000 and about 400,000, a mole percent unsaturation of between about 2.0 and about 2.5 and a Mooney Viscosity (ML 8 min. at 212 F.) of between about 41 and about 49. Commercial grades of butyl rubber are prepared at about -100 C. in methyl chloride diluent using a catalyst solution of aluminum chloride in methyl chloride.

l 6 Example 15 An experiment similar to that of \Example 14 was carried out wherein the t-butanol and t-butyl chloride were added in an equimolar mixture dropwise to a charge of isobutene and AlEt Cl in methyl chloride at 5 0 C. Small amounts of very low molecular weight polymer were formed.

Example 16 To a charge of 0.03 mole isobutene and 0.00024 mole AlEt Cl was added, dropwise, 0.007 mole of acetyl chloride (CH COCI) at C. No polymerization took place nor could polymerization be effected by the addition of 0.007 mole of t-butyl chloride. Increasing the temperature to 30" C. had no effect.

Example 17 Example 18 To a charge of 1.25 moles of isobutene in 200 ml. of methyl chloride was added 0.005 mole of nitroethane (C H NO at 50 C. After thermoequilibration, 0.02 mole AlEt Cl was introduced. Yellow color developed immediately indicating complex formation but no polymer was formed. Stirring was continued for 20 minutes with no polymer formation. The addition of 0.002 mole of t-butyl chloride resulted in the slow polymerization of a polymer having a low molecular weight, i.e., 51,000.

Example '19 The experiment of Example 18 was repeated at temper- TABLE XII Experimental butyls, Commercial butyls, feed feed Feed B-8 B-8 B-fi Butyl 218 Butyl 325 Temperature, C 78 78 -100 -100 Cure at 307 F.:

10 minutes:

Tensile, p.s.i 2, 420 2, 750 2, 340 2, 460 2, 230 300% modulus, p.s.1 890 950 520 370 1, 150 Elongation, percent 660 670 780 860 710 20 minutes:

Tensile, p.s.i 2, 290 2, 710 2, 530 2, 660 2, 360 300% modulus, p.s.i 1, 370 1, 300 730 1, 380 Elongation, percent 470 500 630 690 520 40 minutes:

Tensile, p.s.1 2. 290 2, 460 2, 440 2, 690 2, 340 300% modulus, p.s.i 1,830 1, 930 1, 340 1, 170 1, s20 Elongation, percent 380 390 490 570 380 60 minutes:

Tensile, p.s.i 2, 610 2, 420 2, 730 2, 470 300% modulus, p.s.i 2, 550 1, 630 1, 270 2, 210 Elongation, percent 330 4 0 550 370 From the data in Tables XI and XII, it can be seen that the use of the instant novel catalyst system results in the production of butyl type rubbers having physical properties which compare favorably to commercially available butyl rubbers.

Example 14 To a charge of 0.03 mole isobutene and 0.000238 mole AlEt Cl in 2.5 ml methyl chloride there was added 0.009 mole t-butanol at 50 C. No reaction occurred. When 0.0096 mole of t-butyl chloride was added to the above mixture, no reaction occurred. No polymerization was apparent when the temperature was raised to 27 C.

electron rich oxygen is more favored than reactions leading to carbonium ions.

Example 20 About 2 ml. of isobutylene dissolved in ml. of chlorobenzene was placed in a test tube, cooled to -35 C. and 0.2 ml. of catalyst solution (1 ml. of Al-Et Cl in 9 ml. of chlorobenzene) added. No reaction took place as evidenced by no precipitation upon the addition of copious amounts of methanol.

Example 21 Example was repeated except that after holding the reactants and catalyst at -35 C. for 10 minutes, 2 drops of cocatalyst promoter solution (0.5 ml. t-butyl chloride plus 9.5 ml. chlorobenzene) was added. Polymer formed immediately with a temperature rise to 8 C. The polymer was precipitated with methanol. The product was a white polymer having a molecular weight of about- 171,200. The yield was 0.76 g. (53.5% conversion).

This experiment clearly demonstrates that organic halogen compounds such as chlorobenzene which do not have dissociable halogens are ineffective as promoters despite the fact that they have a dipole moment greater than 1.

Example 22 About 100 ml. of an isobutylene-isoprene mixture (97 vol. percent isobutylene/3 vol. percent isoprene) was added dropwise to 100 ml. of pentane containing 0.01 mole of AlEt Cl. No reaction occurred for 73 minutes at -50 C. Upon the addition of 1.5 10 moles of cocatalyst (HCl dissolved in pentane) an immediate explosive polymerization occurred.

Example 23 The experiment of Example 22 was repeated using methyl chloride as the solvent. No cocatalyst was added. No polymerization occurred.

Examples 22 and 23 further illustrate that it is the proper selection of cocatalyst and not the dipole moment of the solvent which is important in the polymerization reaction. Pentane has a null dipole moment whereas methyl chloride has a dipole moment of 1.85.

Example 24 Unpurified ethyl chloride contains HCl as an impurity residue from the manufacturing process. A quantity of ethyl chloride, for use as solvent, was treated with KOH to remove most of the HCl. Two experiments were then performed to establish that it is the impurity (HCl) which aids in polymerization and not the ethyl chloride.

(A) About 100 ml. of the isobutylene-isoprene mixture of Example 23 was added dropwise to 100 ml. of unpurified ethyl chloride containing 0.01 mole AlEt Cl, the entire reactant mixture being held at 50 C. Polymerization occurred and after a reaction time of 60 minutes 72.0% yield was obtained.

(B) The experiment (A) above was repeated using as a cocatalyst ethyl chloride which had been treated with 18 the KOH to reduce the H-Cl content. After minutes the polymer yield was only 16%.

These data demonstrate that ethyl chloride is an uneffective promoter and that its effectiveness as a promoter is dependent on the HCl impurity content.

Example 25 A stock solution comprising 70 ml. isobutene, 220 ml. of pentane and 1.3 ml. of AlEt Cl dissolved in 10 ml. of pentane was prepared. Addition of the catalyst was made after cooling the solvent-monomer solution to -50 C.

About 1.2 ml. of a solution of 0.1 ml tertiary butyl chloride in 50 ml. pentane (equivalent to 29.4 10 mole t-butyl chloride) was added to the stock solution as a promoter. Polymerization was instantaneous with 22.8% conversion. The polymer formed had a high molecular weight.

Example 26 The experiment of Example 25 was repeated except that instead of t-butyl chloride, ethyl chloride which had been purified by passing it over a 5 A. molecular sieve was used as the promoter. No polymerization took place.

Example 27 A stock solution comprising 50 ml. of isobutene and 0.72 ml. of AlEt Cl dissolved in 50 ml. of methyl chloride was cooled to 50 C. Ten drops (ca. 0.3 ml.) of ethyl chloride which had been purified by passing over a 5 A. molecular sieve were added to the solution. No polymerization took place.

Example 28 The experiment of Example 27 was repeated except that instead of ethyl chloride, about 0.12 ml. of t-butyl chloride was added as a promoter. Instantaneous polymerization resulted in a polymer having a molecular weight of 450,000.

Examples 25-28 demonstrate that (1) ethyl chloride which has been purified is not a catalyst promoter and (2) the dipole moment of the solvent is not a critical factor. Pentane has a null dipole moment but it was possible to initiate polymerization in the solvent. On the other hand, no polymerization took place in methyl chloride (a solvent with a dipole moment greater than 1) until t-butyl chloride was added.

Example 29 Various runs were made with selected monomers using the catalyst system of the invention. The monomers included propylene, butadiene, isoprene, styrene, alphamethyl styrene and cyclopentadiene.

The catalyst (0.13 ml. AlEt Cl) was dissolved in methyl chloride to which was added 0.125 mole of the particular of monomer. The volume of the reactant mixture was brought up to 20 ml. at -50 C. Promoter was then added and polymerization allowed to continue for 10 minutes after which time polymerization was quenched by the addition of cold methanol. The results of these experiments are shown in Tables XIIIa and XIIIb.

TABLE XIIIa [Polymerization of various monomers with AlEtgOl and various cocatalysts] Propylene Isobutene Styrene Monomer promoter a b c d a b c d a b c 6.

H01 9. 6X10 (2) 0 0 4X10- 164, 200 292960 4X10- 74 186, 000 5, 059

CH 1. 1Xl0- 0033 3 4. 5Xl0- 014 3. 4 1. 6X10 04 270 CHCl CHZ=CHCII2OI 2. 5X10- 9. 1X10- 019 210 2. 4X10 15 64, 000

CH CHzil-CHz-Cl 5X10 0 0 1. 7X10 069 3, 940 5X10 26 52, 000

TABLE XIIIa-Contlnued Monomer Propylene Isobutene Styrene promoter a b o d a b c d a b o d CH CH;C JCI 9.1)(10 .655 720 900 4. 5X10 .59 132, 000 380Xl 6.0X10- 1.05 155,000 11,690

O Hz

-CHzCl 4 3X10" 3.15 734, 000 3'53Xl0- 2. 2X10" 0.52 240, 000 16, 569

H JCl 6. 8X10 0 0 0 6. 7X10" 52 78, 000 727 l0- 4. 6X10 37 82, 000

H JCl 4. 2X10- 0 0 O 2. 8 10- .35 12, 600 250 1o- 2. 8X10- 51 183,000 19,086

(:JCl 1.8)(10' 0 0 0 3. 1X10 Low 9X10 .06 650 1 Polyisobutene molecular weights are viscosity average values.

2 Small amount of 0 3 Trace oil. 4 Benzyl chloride. 5 Polymerizes.

Very small amount.

NorE.a =Moles of promoter; 1) g. of product; 0 promoter efficiency gJmole; d =molecular weight.

TABLE XIIIb [Polymerization of various monomers with AlEtgOl and various promoters] Butadiene Isoprene a-Methyl styrene Monomer promoter a b o d a b e (1 oyclopentadiene HCl 1. 2Xl0- 21 1,800 1 12, 800 1. 8 l0- 17 9, 660 2 14, 620 Immediate polymerization on AlEtgOl introduction. No promoter addition is necessary to obtain polymer. r OHC1 1. 1 10- 0 0 1. 4X10- 001 86 CH2 OH:-CH:gC1 6. 2X10- 21 40, (J00 e.1 1o 11 18 r CHzCCHzCl 1. 5 10- 34 228 5. 2X1O- 18 35 Z 12, 800

(7H 011 -0-01 4. 5X10- 86 1, 900 4. 5X10- 2. 38 5, 300

CH; C1 4. 4 1O- 18 4, 130 20, 560 8. 7X10' 37 4, 300

1'1 (|]Cl 4. 5 l0- 36 807 4. 6X10- 1. 33 2, 260

CH (IJCI 5. 6X10 41 742 2. 8X10- 52 1, 850

i (]JCl 7. 2X10- 0 0 9X10" 0 0 1 127 gel. 2 6% gel. 66% gel. 4 Insoluble. 5 91% gel. 6 61% gel No'rE.a=Moles of promoter; b=g. of product; c=Promoter efiicieney gJmole; d=Molecular weight.

Based on these data, it appears that our catalyst system (A1Et Cl plus promoter) is suitable for use with any monomer whose polymerization is catonically initiated. It is obvious to one skilled in the art that not only may homopolymers be formed but copolymers of the suitable (cationically polymerizable) monomers may also be formed.

Surprisingly, it is noted that a-methyl styrene and cyclo- 70 pentadiene may be polymerized without the use of a promoter to high molecular weights. This result is wholly unexpected since styrene itself cannot be polymerized by AlEt C1 alone and prior art methods of polymerizing (rt-methyl styrene do not result in such high molecular weights.

One skilled in the art will readily recognize that AlEt Cl can be used as a catalyst to form copolymers of a-methyl styrene and cyclopentadiene. It is known to form crosslinked styrene polymers using divinyl benzene as the crosslinking agent. Similarly, a crosslinked a-methyl styrene may be prepared by the addition of about 1 to 10 wt. percent preferably about 1-4 wt. percent of divinyl benzene to the monomer mix.

Although other cationally polymerizable monomers ordinarily require the use of a promoter in conjunction with AlEt Cl it is possible to copolymerize minor amounts of these monomers (i.e. isoprene, butadiene, isobutene) with a major portion of a-methyl styrene or cyclopentadiene. Preferably, less than 10 wt. percent of the second monomer is employed. More preferably about 0.5 to about 4 Wt. percent of a cationically polymerizable monomer is co-reacted with m-methyl styrene or cyclopentadiene.

A particularly advantageous polymer is formed by reacting about 0.5 to about 4 wt. percent of isoprene or bicyclopentadiene with styrene or ot-methyl styrene to form a high molecular weight styrene type polymer.

Example 30 A stock solution was prepared consisting of 50 ml. of 3-methyl butene-l dissolved in 200 ml. of methyl chloride to which catalyst (1.3 ml. AlEt Cl in 10 ml. of methyl chloride) was added.

A cocatalyst solution was prepared by dissolving 0.5 ml. t-butyl chloride in 50 ml. of methyl chloride.

A. 10 milliliters of stock solution were cooled to -50 C. About 3.7 ml. (ca. 3.3 1S mole t-butyl chloride) of cocatalyst solution were added. Instantaneous polymerization resulted in 1.1 g. of polymer (ca. 82.6% conversion) having a molecular weight of 7860.

While a number of specific embodiments of the present invention have been hereinbefore described, it is obviously possible to employ other embodiments and various equivalent modifications and variations thereof without departing from the spirit of the invention.

What is claimed is:

1. A process for the production of polymer products of cationically polymerizable monomers which comprises polymerizing said monomers with a catalyst systern consisting essentially of (1) a catalyst of the type Al(M) R, where M is a C to C alkyl and R is selected from the group consisting of M, hydrogen and halogen and (2) a promoter selected from the group consisting of (a) dihalomethanes and (b) organic halogenides having at least one dissociable halogen atom, represented by the following structural formula:

wherein X is halogen, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl and C to C alkenyl, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl, C to C alkenyl and phenylal-kyl and R is selected from the group consisting of C to C alkyl, C to C alkenyl, phenyl, phenylalkyl, alkylphenyl, C to C cycloalkyl and wherein R R and X are as defined above and R is selected from the group consisting of phenylene, biphenyl, a, w-diphenylalkane and -(CH wherein n is an integer of from 1 to 10, at a temperature of between about C. and about 100 C., the mole ratio of said promoter to said catalyst being from about 0.0001 :1 to about 30:1.

2. The process of claim 1 wherein the monomer is a C to C monoolefin.

3. The process of claim 1 wherein the catalyst is diethyl aluminum chloride.

4. The process of claim 1 wherein the promoter is tertiary butyl chloride.

5. The process of claim 1 wherein the temperature is between about 27 C. and about 78 C.

6. A process for the production of polymer products of monoolefins which comprises, polymerizing a monomer mixture of a major proportion of a C to C isoolefin and a minor proportion of a C to C conjugated diolefin with a catalyst system consisting essentially of (l) a catalyst of the type Al(M) R, where M is a C to C alkyl and R is selected from the group consisting of M, hydrogen and halogen and (2) a promoter selected from the group consisting of (a) dihalomethanes and (b) organic halogenides having at least one dissociable halogen atom represented by the following structural formula:

wherein X is halogen, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl and C to C alkenyl, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl C to C alkenyl and phenylalkyl and R is selected from the group consisting of C to C alkyl, C to C alkenyl phenyl, phenylalkyl,

alkylphenyl, C to C cycloalkyl and R1 X'JJ*-R4 wherein R R and X are as defined above and R is selected from the group consisting of phenylene, biphenyl, a,w-diphenylalkane and (CH wherein n is an integer of from 1 to 10, at a temperature of between about 0 C. and about l00 C., the mole ratio of said promoter to said catalyst being from about 0.0001 :1 to about 30:1.

7. The process of claim 6 wherein the isoolefin is isobutene and the diolefin is isoprene.

8. The process of claim 1 wherein the monomer is isobutene, isoprene, styrene, 3-methyl butene-l, or mixtures thereof.

9. The catalyst system of claim 1 wherein the promoter is dichloromethane.

10. A process for the production of polymers which comprises polymerizing monomers selected from the group consisting of a-methyl styrene, cyclopentadiene and mixtures thereof with a catalyst consisting essentially of organoaluminum compounds having the general formula Al(M) R where M is a C to C alkyl and R is selected from the group consisting of M, hydrogen and halogen.

11. The process of claim 10 wherein the monomer is a-methyl styrene in combination with a minor amount of diolefin.

12. The process of claim 11 wherein the diolefin is butadiene, isoprene, bicyclopentadiene or mixtures thereof present at about 0.5 to about 4 wt. percent.

13. The process of claim 12 wherein a catalyst promoter is added wherein said promoter is selected from the group consisting of 1) dihalomethanes and (2) organic halogenides, having at least one dissociable halogen atom, represented by the general formula:

R1 R2 -X Ra wherein X is halogen, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl and C to C alkenyl, R is selected from the group consisting of hydrogen, C to C alkyl, phenyl, C to C alkenyl and phenylalkyl and R is selected from the group consisting of C 23 to C alkyl, C to C alkenyl, phenyl, phenylalkyl, alkylphenyl, C to C cycloalkyl and R3 wherein R R and X are as defined above and R is selected from the group consisting of phenylene, biphenyl, a,w-dipheny1alkane and -(CH wherein n is an integer of from 1 to 10, at a temperature of between about 0 C. and about -100 C., the mole ratio of said promoter to said catalyst being from about 0.0001 :1 to about 30: 1.

14. The product of claim 12. 15. The product of claim 13.

24 References Cited UNITED STATES PATENTS 2,765,297 5/1952 Heiligrnann et a1. 260-94.9 2,938,020 5/ 1960 Matlack 26094.9 3,349,064 10/1967 Gumboldt et a1. 260-807 3,3 54,139 11/1967 Vandenberg 260-949 3,426,007 2/1969 Kennedy 26085.3

JOSEPH L. SCHOFER, Primary Examiner 10 R. A. GAITHER, Assistant Examiner US. Cl. X.R. 

